CLAIMS of life on Mars have been boosted after the discovery of a ‘clam-like shell’ in NASA images beamed back from the Red Planet.

UFO hunters claim the revelation proves there was once life on the planet, in the latest in a long line of so-called discoveries.

As more people scour Martian images placed on line by NASA desperate for evidence of other lifeforms, the shell follows the location of a monkey, bear, mouse, crab, and scorpion, all apparently found in Mars photographs.

The "clam" was posted to UFO websites alongside pictures of the real thing as a comparison, but others have suggested it could be a buried statue's hand or gauntlet.

Other recent discoveries in the pictures sent back to Earth by the Curiosity Rover - a four-wheel-drive dried scouring the planet for NASA - then placed online by the US space agency include a partially-buried guinea pig stature and a Mount Rushmore-style rocky outcrop.